Carbon isotope composition of Antarctic plants

Carbon isotope compositions of Antarctic land plants are first reported. Th e most interesting feature is the isotope specificity of the species. For e xample Usnea antarctica from different locations shows relatively narrow ra nge of the delta(13)C-values from -22.44 to -21.29 parts per thousand (7 sa mples), Drepanocladus sp. from -24.86 to -23.49 parts per thousand (8 sampl es), and Andreaea depressincrvis from -23.87 to -23.23 parts per thousand ( 3 samples) etc. Usually, in inhabited lands and parts of the world with ric h flora and developed soil, isotopic specificity of species is masked by va riations of carbon isotope composition of CO2. In Antarctic conditions infl uence of local sources of CO2 on the isotope composition of CO2 is appeared to be minimal. Therefore the delta(13)C-variations inherent to individual plant physiology and biochemistry can be distinguished on the background of the stable level of the atmospheric CO2 delta(13)C-value. The latter is be st to reflect the global state of the carbon cycle. Copyright (C) 2000 Else vier Science Ltd.